In rural and urban areas, it is often necessary to wash them in order to keep them in the open. In the heavily polluted industrial and coastal areas, the surface can be very dirty and even rust. But to obtain the aesthetic effect of outdoor environment, it is necessary to use nickel stainless steel. Therefore, 304 stainless steel is widely used in curtain walls, side walls, roofs and other building applications, but in corrosive industrial or marine atmospheres, it is better to use 316 stainless steel. There are several design criteria including 304 and 316 stainless steel.

Q:The difference between 12Cr1MoVG alloy steel tube and 15CrMo

With this kind of steel manufacturing products, usually by heat treatment (normalizing and tempering); parts made before use, usually need to go through refining or chemical surface treatment (carburizing and nitriding), surface quenching or high-frequency quenching treatment. Therefore, according to the chemical composition (mainly carbon content), heat treatment process and use of different, such steel can be roughly divided into carburizing, quenching and tempering and nitriding steel three.

Q:Why can't stainless steel be put together with carbon steel tube?

1, the potential difference is: potential "stainless steel tube" and the negative potential "carbon steel" coupled "stainless steel", "a cathode carbon steel tube" is anode potentials of the two difference the greater the galvanic corrosion is bigger.2. An electronic passage formed by wire connection or direct contact. The carbon in the carbon steel tube loses its electrons to the stainless steel tube and the surface is absorbed by the etchant.3. Electrolyte: the contact area of two metals is covered or submerged by electrolyte. The iron in the carbon tube loses electrons to form ions into the solution, and the electrons on the surface of the stainless steel tubes are taken away by the corrosive agents in the electrolyte (such as oxygen in the air). Electrolytes become ionic channels.

In the connection work, strengthening ring joint stiffness, high bearing capacity and no parts through the tube, it is especially suitable for the small diameter steel tube concrete column structure, complex engineering projects, especially those in the pump sending pouring construction method, which is more important, it has a basic guarantee strictly for the quality of concrete construction. When concrete columns with larger diameter, ring type joint construction steel is large strengthened, so as to make the project construction become more complex, and the connection between the longitudinal rebars becomes cumbersome.

Q:The outer circle of a seamless steel pipe 50 head into the outer circle of the 40 to close

That is, according to the production process of different classification, different from hot rolling (expansion) pipe. In the process of expanding the tube or raw material tube, it is processed by multiple cold drawing, usually on single chain or double chain cold drawn machine of 0.5 ~ 100T. Cold rolled steel pipe (DIAL) in general, steel pipe for low and medium pressure boiler tube, high-pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking tube, machining pipe, thick wall pipe, small diameter and cold drawn steel tube also includes other tubes, carbon thin-walled steel, alloy thin-walled steel pipe, stainless steel pipe, special-shaped wall steel pipe. The outside diameter of cold drawn steel tube wall thickness to 6mm, to 0.25mm, to 5mm diameter thin-walled tube wall thickness is less than 0.25mm in size, accuracy and surface quality were significantly better than the hot (expanding) tube, but by the process control, its diameter and length are limited.

1, the process is different, one is chemical treatment, one is physical treatment; hot-dip galvanized coating is reliable, not easy to fall off2, hot-dip galvanized coating thickness, so strong corrosion resistance. And zinc plating (electroplating) coating evenly, surface quality is better, coating thickness is generally between a few microns to more than ten microns.3 hot galvanizing is a chemical process, which belongs to electrochemical reaction. Zinc plating is a physical treatment, just brush a layer of zinc on the surface, there is no galvanizing inside, so the zinc layer is easy to fall off. Hot-dip galvanizing is used in building construction.4 、 hot galvanized pipe is to make molten metal and iron matrix reaction and produce alloy layer, so that the substrate and coating two combination.

Q:How seamless steel tube is formed?

Hot drawing or cold drawing. The so-called cold is the billet from the thick wall tube is not heated, oil lubrication, with a steel sleeve inside, gradually elongated. Hot drawing is to make the billet tube red, do such work, generally thick wall applicable.